1. Field of the Invention
The present invention relates to cellular phones, personal digital assistants (PDAs), tablet PCs, mobile terminal devices such as electronic book terminals, storage media holding computer programs preferably for use in the mobile terminal devices, and display control methods preferably used in the mobile terminal devices.
2. Disclosure of Related Art
In recent years, there are an increasing number of mobile terminal devices with touch panels, instead of operation keys.
Generally, a touch panel-type mobile terminal device with an acceleration sensor allows the display direction of a screen on the touch panel to be changed in a user-friendly manner, depending on the orientation of the device main body held by a user with respect to the ground.
On a mobile terminal device with a touch panel, a user can select one of a plurality of keyboards different in key layout and display the selected keyboard on the screen. The keyboard displayed on the screen is decided in size and shape depending on the aspect ratio of the screen.
For example, a QWERTY keyboard has a larger number of keys arranged in the horizontal direction than those arranged in the vertical direction. Accordingly, when the screen is in portrait orientation, there are extremely small intervals between keys horizontally adjacent to each other. In such a state, a user may be likely to perform incorrect input by pressing wrong keys.
Accordingly, it is desired to take preventive measures on a mobile terminal device on which a keyboard is displayed in various forms so as to avoid occurrence of repeated incorrect input depending on the display form of the keyboard.